CAN BE SHORTENED TO APPROXIMATELY 13 3/4". FITS FORMULA MAZDA. These universal halfshafts are made from 4340 steel, and heat treated to Rockwell 44-46 for maximum strength and toughness. They have extra length splines so that they can be shortened to accommodate nearly any length from 13-12" to 22". If desired, Taylor Race Engineering can do the machine work for you.